Waterproof roofing materials derived from rolls and laid across a roof structure, with their edges overlapped and sealed, have been used for several years. More recently some of these roofing materials are made with an entire adhesive undercoating layer, and during their placement on a roof structure, the adhesive undercoating is preheated throughout the width of the roll of roofing material.
In 1963, Walter Kauer in his U.S. Pat. No. 3,097,986 described and illustrated his sheet applying apparatus used in applying a sheet of roofing paper, derived from a roll, to a roof surface. His apparatus was self contained, carrying both the roll of roofing paper and a heating unit. His apparatus automatically applied a uniform heat both to the roofing paper and to the roof before the roofing paper was reliably pressed against the roof surface by utilizing his apparatus. The heating unit position was adjusted as the roofing roll decreased in diameter, so the distance between the heat discharge and the exterior of the roofing roll remained substantially unchanged. A carriage releasibly supported the roll of roofing paper and positioned the heating fluid tank of the heating unit directly over the roll of roofing paper. Transversely spaced wheels advanced ahead of the roofing roll and transversely arranged pressing rolls followed behind the roofing roll.
In 1982, William E. Kugler and James M. Pacello in their U.S. Pat. No. 4,354,893 illustrated and described their combination roofing material unrolling and heat applying apparatus, directed to the like purpose to be served by using Walter Kauer's sheet applying apparatus. They provided a way to move the heat discharge toward and away from a roofing roll and not be required to keep the heat discharge, via pivotable spaced burners, in a parallel relationship to the roofing roll. Their carriage releasibly supported the roll of roofing paper, which in turn provided the following rolling support of the carriage. The leading support was provided by two spaced wheels. As so illustrated their carriage did not support a tank containing a heating fluid.
Before 1963 and through 1982, other persons in U.S. patents have illustrated and disclosed their apparatus designed to seal the overlapping edges of roofing sheets already laid in place, such as:
Messrs. Stebbins and Yeager's apparatus for laying sheet material set forth in their U.S. Pat. No. 2,084,625, wherein they heated the overlapping edges;
John N. Lang's apparatus for sealing lap joints of fusible roofing sheets as disclosed in his U.S. Pat. No. 4,087,309, wherein the fuel source was carried on his carriage;
Donald R. Tabor's roofing material handling and sealing machine as shown and described in his U.S. Pat. No. 4,204,904, wherein the leading two wheels straddled the overlapping edge portions of the roofing material and the rear single wheel pressed against these overlapping edge portions;
John N. Lang's apparatus for sealing lap joints of fusible roofing sheets, as disclosed in another one of his U.S. Pat. Nos., 4,239,581, which also carried a fuel source and two flame chambers; and
Dale T. Kortepeter's machine for applying roofing material, as disclosed in U.S. Pat. No. 4,259,142, separated and heated overlying edges of prelaid roofing material sheets to soften their facing layers of bitumen material, and thereafter pressed these overlying heated edges together upon the passage of a trailing pressing roller.
Although these prior patentees provided useful apparatus to be used in applying sheet roofing material, derived from rolls, which required heating at least at the edges, and/or across their roll widths, there remained a need for apparatus which could be reliably used more conveniently to effectively and accurately lay roofing material as it was unrolled and as it was heated and sealed along the overlapping edges and across the width of each sheet.